All components of a rotating machine are primarily machined along the rotational axis of manufacturing machinery thereof. A dynamic balancing apparatus is used to measure the position, i.e., angle, and magnitude of an unbalanced mass which exists with respect to an actual rotational axis after the components are assembled.
A dynamic balancing method is a theoretical method which is used in the dynamic balancing apparatus to measure the position, and magnitude of a rotating unbalanced mass.
In order to measure the unbalancing mass, most commercially used dynamic balancing apparatuses are used to measure a centrifugal force generated from the unbalanced mass when a balancing test piece is rotated at a certain speed, or indirectly measure the vibration of a support generated by the centrifugal force, thereby estimating the position and magnitude of an unbalanced mass.
In the conventional balancing method, if a rotational body has a very heavy weight, it may be impossible to directly rotate the rotational body, and thus it needs an additional device for rotating the rotational body very slowly and gradually.
Particularly, in case of fans or blowers, since the centrifugal force or corresponding vibration is disturbed by air flow generated when they are rotated, it is difficult to measure the unbalanced mass accurately.
Furthermore, since the conventional balancing apparatus needs an accelerating time until reaching a certain rotating speed from the initial state and a decelerating time which is required to stop the rotating state safely, it takes lots of time to complete the dynamic balancing.